Process of manufacturing cellulose



'Patent ed Feb. 17, 1925.

UNITED STATES RICH ARD M'tl'L LER, OFELENBURG, GERMANY.

PROCESS OF MANUFACTURING CELLULOSE.

No Drawing.

To all whom it may concern:

Be itknown that I, RICHARD Momma. a citizen of 'Wurttemberg, and residing at Eilenburg, Prov. Sachsen, Germany, have i invented certain new and useful Improvements in Processes of Manufacturing Cellulose, of which the following is a specification.

It is already known that cellulose can be produced out of wood by treating the latter with nitric acid or mixtures of nitric and sulphuric acids, but as such a process is not profitable on accountof the high price of nitric acid it. has not hitherto been employed on a largescale.

It has been found, however; that the di luted mixture of sulphuric and nitric acids, or diluted nitric acid alone, such as the waste washing-liquid troin the nitration process, which, as a result of its extremeidilution, is completely without value, and. is even a nuisance to the works in question because it has to be neutralized at considerable expense to avoid polluting the rivers, etc.. is very suitablefor the treatment of wood, placed in the liquid in the usual form of very small pieces, so changing the lignose that it can be extracted, together with the other incrus tations, pyrolignic acid, etc., without difficulty, even with cold, diluted alkalies. Firwood, for instance, which had lain in a mixture of 3% nitric acid and 10% sulphuric acid for ltdays at about 20 centigrade, was so changed that treatment with a solution of caustic soda resulted in a yield of about 52%. of excellent cellulose. Still Weaker acids, when ellowed to. ,act longer,

Application filed. May 10, 1921. Serial No. 468,349.

have also resulted-in good disintegration and excellent yields. In this manner it 18 possible, when the diluted acids are sub- 40 Fequently again used as washing-liquid for the nitration products to obtain up to three times the quantity of cellulose to one part of nitro-cel-lulose and tosecure a satisfactory yield of good cellulose for the nitration process and for other purposes. 7

Patent claim. I

1. The process comprising the following steps: nitrating cellulose or the like by the action of nitrating acid, washing the nitrated product and digesting Wood by treatment with the wash liquor thereby'to produce a further supply of cellulose.

2. The process comprising the following steps: nitrating cellulose 'or the like by the action of nitrating acid, washing the nitrated product, digesting wood by treatment with the wash liquor thereby to produce a further supply of cellulose and utilizing the liquor from the digestion step. to wash further nitrated material and so on.

3. The process ofmanufacturing cellulose from wood characterized by the step of disintegrating the Wood by treatment with wash liquor from nitration processes.

4. A reagent for the production of cellulose from wood consisting of the acidulous wash liquor produced in nitration processes. In testimony whereof I aifix my signature in presenceof two witnesses. v

' DR; RICHARD MULLER. Witnesses:

A. CONRAD AMBER, W RNER Gnoss. 

